Guideline-marker drawing instrument



June 22, 1965 F, SQRENSEN 3,190,001

GUIDELINE-MARKER DRAWING INSTRUMENT Filed Jan. 20, 1964 INVENTOR. EARL E SORENSEN A TTORNE'Y United States Patent Office 3,l9,fidl Patented June 22, 1965 3,l9il,tl0l GELlNE-MARKER DRAWHNG ENSTRUMENT Earl F. Sorensen, 24ll3'Fenton St, Edgewater, Colo. Filed .lan. Ztl, i954, Ser. No. 338,818 2 Claims. (ci. 33-41 The present invention relates to a guideline-marker for lettering work and, more particularly, to a drawing instrument that will be useful to mark lightweight guide lines on drawing paper. Such guide lines may be conveniently used in the layout and execution of lettering work on such drawings.

It is recognized that others have previously provided different types of drawing aids that might be used for the placement of guide lines on drawing surfaces. In general, such prior devices have provided spaced apart openings, slots or guide surfaces so that drawing pencils might be applied to such guide elements to obtain lettering guide lines on a drawing surface that are of a regular spacing as needed for the desired size of letter. Most of such instruments have made it necessary to scribe each individual line by a separate stroke of the drawing pencil. In some types of previous drawing aids an entire surface of the guide element contacts the drawing sheet and is moved twice across the face of the drawing sheet for each stroke line.

While good and serviceable lettering guide lines may be made with most prior types of instruments, it is believed that the actual placement of such drawing guide lines can be accomplished more efficiently, neater and with greater rapidity through use of a modified type of drawing aid.

Accordingly, it is an object of this invention to provide an improved type of drawing instrument which makes it possible to speedily and efficiently apply guide lines to drawing plate surfaces.

Another object of this invention is to provide a guideline-marker which may be readily adjusted to provide a plurality of guide lines simultaneously on a drawing surface at properly spaced and regulated distances apart.

A specific object of this invention is to provide a drawing instrument which will facilitate the making of a plurality of faint guide lines simultaneously on a drawing sheet in regulated spaced positions apart through use of metallic marking elements which Wear only slightly with use.

A further specific object of this invention is to provide a drawing instrument incorporating novel selective distance, indexing and holding mechanisms.

Another object of this invention is to provide a distance indexing mechanism in connection with spring biased members wherein the biasing spring pressure tends to hold the indexing mechanism in desired selected engagement.

A further specific object of the invention is to provide a novel distance indexing and locking mechanism for use on drawing instruments.

A still further object of this invention is to provide spring biased members for holding line marking elements in which the distance between the spring biased members may be selectively regulated through use of an index locking mechanism working cooperatively with the spring biased members.

Further objects and advantages of the present invention will be apparent from the appended description and drawings, in which FIG. 1 is a front elevation of a preferred embodiment of the invention,

FIG. 2 is a side elevation showing further features of the preferred embodiment,

FIG. 3 is a rear elevation showing such embodiment,

FIG. 4 is a partial cross-sectional elevation taken along the line 44 of FIG. 2 showing the index-locking member, and

FIG. 5 is a cross-sectional elevation taken along the line 5-5 of FIG. 2 illustrating means for holding the line marking elements.

Briefly stated, the present invention provides a drawing instrument that is specifically useful to place a plurality of lightweight guide lines on a drawing surface. For the actual making of the lines the instrument provides a plurality of long-wearing metallic marker elements that will make a desirable light line on drawing surfaces. The marker elements are held by support members or legs which are themselves structurally joined each to each but which are biased apart at their free ends by an exerted spring pressure. The spacing between the free ends of the separate supports and, accordingly, the spacing of the line marking elements is selectively adjusted, regulated and maintained through use of an index-locking mechanism. Such index-locking mechanism includes a bar having a plurality of longitudinally spaced. notches adapted for engagement with a catch element on one of said supports. The notched bar is at a first end provided with a stop shoulder, while a head of enlarged size is provided at the opposite end so that the divergence of the support elements will be limited thereby. The head is further positioned for engagement with a raised surface, pin or dimple on the adjacent support member whereby an eccentric force will be applied against the head and thereby against the bar to hold and maintain the notches and catch in their selected locked position.

A specific and preferred embodiment of the invention is shown in the accompanying drawings. The main detailed structural features of such device are shown in FIGURES 1 through 3. In these figures it will be seen that a guideline-marker 11 is provided with a plurality of support members 12 and 13 which are joined and held together at their top extremity as by a spot: welding or by simple pressed engagement in a knurled operator knob 16. The support members 12 and 13 are preferably made of spring material so that a spring force will be exerted by such support members which tends to hold the free ends 22 and 23 of such members apart. It is these free ends, together with the pincher elements 28 and 29, which hold, guide and support line marking elements 26 and 27.

As shown in FEGURES 2 and 5, the pincher elements 28 and 29 may be brought securely against the side faces 32 and 33 of the marker elements by tightening the lock screws 31 which extend through the side faces 32 and 33 and are threadedly received in the pinchers 28 and 29. This assembly, together with the fulcrum provided by the extensions 34 and 35, tends to hold the marker elements 26 and 27 securely in position with respect to the free ends 22 and 23 of the support members 12 and 13. The assembly further makes it possible to adjust the distance for the extension of the marker elements past the free ends 22 and 23 in order to compensate for the wear of such elements. Loosening of the lock screws 31 permits adjustment in the effective length of the marker elements 26 and 27. Accordingly, compensations may be made for any wear of the elements so the space adjustments can be maintained irrespective of marker element wear.

While the capacity to make adjustments in advantage ous, it has proved desirable to provide long wearing types of marker elements so that the need for adjustment can be minimized. Since the weight of the lettering guide lines required is quite light, it has been found that certain types of metallic materials can be beneficially used for the marker elements. With proper selection of materials, some of the aluminum alloys, as

'Well as various lead, tin, and lead-antimony alloys,

may be used to make an adequate line without undue wear of the contact points 36 and 37. The faint line made by such alloys on a drawing surface can be easily seen by the draftsman, but it is noted that such line is unobtrusive or even 'unnoticeable to the casual observer. Since it is desirable that the guide lines be unobtrusive, the use of metallic marking elements serves a dual purpose. The provision of a faint line and the absence of wear makes the use of such alloys especially advantageous.

The illustrated embodiment of the invention obviously may be used to make two spaced apart guide lines by the simple expedient of moving one of such marker eleinents along a guide and in contact with a drawing sheet. If the support members 12 and 13 are held a regulated distance apart, the guide lines made will be regularly spaced, and accordingly, accurate lettering may result.

An important feature of the present invention is embodied in the index-locking mechanism used for holding support members 12 and 13 and, accordingly, the marking elements 26 and 27 at selected regulated distances apart. A preferred locking mechanism is illustrated in FIGS. 1 through 4- of the accompanying drawings. Here it will be noted that the index-locking mechanism 41 includes the provision of a bar ele ment 42 which in the present embodiment is of circular cross-section having a plurality of longitudinally spaced cut notches 43 in diametrically opposed faces of such bar. The notches are spaced each from each along one face of the bar 42, and further, it should be noted that the notches on the upper surface of the bar are longitudinally spaced with respect to the notches on the lower surface of the bar. This provides a multiplicity of longitudinally spaced notches 43 whereby the support members 12 and 13 may be held in a corresponding plurality of accurately spaced positions each to each. Since the notches are easily identified, the relative spacing of the marker elements 26 and 27 may likewise be identified and indexed so that the guide lines eventually made will also be spaced apart each from each a closely controlled and regulated distance.

The selection of the desired notches may be easily accomplished by rotating the operator knob 44 at one end of the bar 42. This operator knob is essentially a fiat plate disk having a diameter considerably greater than the diameter of the bar 42 itself. Such knob may be knurled in order to facilitate the rotational and longitudinal placement of the bar as necessary to bring the proper notch 43 into engagement with a catch element 46 disposed on one of the support members 12 for engagement with such notches.

In order to hold the selected notches 43 in position of engagement with the catch plate 46, the spring bias pressure exerted by the support members 12 and 13 is utilized. The outwardly directed spring force is transmitted by the raised pin or dimple 47 to the in board face 48 of the operator knob 44. This off-center point of engagement biases the knob 44 and the attached bar 42 toward a position of secure and maintained engagement between the notches 43 and the lock plate 45. There elements will be held in their desired selected positions by such eccentrically applied spring bias pressure.

Whenever it is desired to change the spacing of the marker elements 26 and 27, the spring pressure may be relieved by the operator so that the knob 4-4 and the bar 42 may be rotated to disengage the notches and lock plate or, further, the bar 42 may be moved reciprocally through the opening 49 in the support member 12 to make longitudinal adjustments in the effective length of the .bar 42.

The structure further provides a stop shoulder 51 at the end of the bar 42 away from the operator knob 44 to prevent inadvertent disassembly of elements of guideline-marker lll. Shoulder 51 is preferably provided by a screw element 52 so that it may be disengaged at times of assembly or disassembly of the marker 11.

The completed assembly provides a mechanism which fully satisfies the stated objectives of the invention, and, accordingly, while the described embodiment is of a presentlypreferred type, it should be obvious that the invention is adaptable for use in different types of draft ing equipment. Further, it will be noted that the invention is adaptable to various modifications and changes. All such modifications, changes and extensions of use are considered to be a part of this invention as set forth in the accompanying claims.

I claim:

1. A drawing instrument comprising a plurality of leg members formed of resilient material, means joining said leg members each to each whereby the resilience of said leg'members exerts a spring force tending to bias said leg members for movement in opposite directions each to each, and an index locking mechanism for holding said leg members in selective adjusted positions as required for various drawing operations, said locking mechanism comprising a bar member extending between said leg members and having a plurality of notches longitudinally disposed along the length of said bar, an operator member on said bar, a catch element on one of said legs for engagement selectively with one of said notches, and a raised element on the other of said legs positioned to act against the operator member of said bar at a point that is non-concentric with respect to said bar whereby the spring force of said legs exerts an eccentric force against said bar for holding said notches and catch in desired selective engagement.

2. A drawing instrument comprising a pair of leg members formed of resilient material, drawing plate contact elements on said leg members, means joining said leg members together whereby the resilience of said leg members exerts a spring force tending to bias said leg members for movement in opposite directions each to each, and an index locking mechanism for holding said leg members and contact elements in selective adjusted positions as required for various drawing operations, said locking mechanism comprising a bar member extending between said leg members and having a plurality of notches longitudinally disposed along opposed surfaces of said bar, an operator member disposed transversely on said bar, a catch element on one of said legs for engagement selectively with one of said notches, and a fixed raised element on the other of said legs positioned to act against the operator member of said bar at a point that is non-concentric with respect to said bar whereby the spring force of said.

legs exerts an eccentric force against said bar for holding said notches and catch in desired selective engagement.

References Cited by the Examiner UNITED STATES PATENTS 275,403 4/83 'Neimeyer s3 153 511,468 12/93 Von Sillich -8 1,072,539 9/13 Webster 33-152 1,081,840 12/13 Koehle an 33-41. 1,102,146 --6/14 Ellis 33- 153 1,501,745 7/24 Carroll "120-83 3,110,111 11/63 Pachter 33 -154 FOREIGN PATENTS 342,964 10/21 Germany 27,125 1910 Great Britain.

722,242 1/55 Great Britain.

363,316 10/38 Italy.

ISAAC LISANN, Primary Examiner. 

1. A DRAWING INSTRUMENT COMPRISING A PLURALITY OF LEG MEMBERS FORMED OF RESILIENT MATERIAL, MEANS JOINING SAID LEG MEMBERS EACH TO EACH WHEREBY THE RESILIENCE OF SAID LEG MEMBERS EXERTS A SPRING FORCE TENDING TO BIAS SAID LEG MEMBERS FOR MOVEMENT IN OPPOSITE DIRECTIONS EACH TO EACH, AND AN INDEX LOCKING MECHANISM FOR HOLDING SAID LEG MEMBERS IN SELECTIVE ADJUSTED POSITIONS AS REQUIRED FOR VARIOUS DRAWING OPERATIONS, SAID LOCKING MECHANISM COMPRISING A BAR MEMBER EXTENDING BETWEEN SAID LEG MEMBERS AND HAVING A PLURALITY OF NOTCHES LONGITUDINALLY DISPOSED ALONG THE LENGTH OF 